Abstract:
On 1 June 2022, a 6.1 magnitude earthquake occurred in Lushan County, Ya'an City, Sichuan Province, with a depth of 17 km. Based on the comprehensive consideration of the earthquake magnitude and the traffic condition of the earthquake area in previous earthquakes, this paper carries out a rapid assessment of the risk level of road landslides in the earthquake affected. The Newmark model was used to calculate the permanent cumulative displacement of rock mass in the study area and to classify the earthquake landslide risk level. The assessment results show that under the influence of the Lushan 6.1 magnitude earthquake, the landslide risk level in the study area gradually decreases from the epicenter to the surrounding area with a similar pattern to the attenuation of ground shaking intensity; the landslide risk level on the north-west side of the study area is significantly higher than that on the south-east side, and this distribution pattern is consistent with the topographic and geomorphological characteristics of the study area; based on the classified risk level, seven high risk areas for road landslides were identified in the study area. Five of the six affected road sections collected fell within the high-risk area of road landslides. The verification showed that the high-risk area of road landslides delineated based on the Newmark model and road network data had a high degree of confidence, and the rapid assessment method of earthquake road landslides could support the deployment of emergency rescue forces and mitigation of losses caused by geological disasters after the earthquake.